Medical progress in the last century has dramatically reduced the morbidity and mortality caused by infectious diseases. On the other hand, infections by bacteria, fungi, protozoa and viruses continue to be the most important factor of mortality in developing countries. Even in developing countries, the rapidly progressing development of resistances against all presently used anti-infective agents generates this state of urgency for the development of novel chemotherapeutic agents for the control of infectious diseases. The enzymes of the recently discovered non-mevalonate pathway of terpene biosynthesis are known to be essential in gram negative bacteria and in Plasmodium spp., and the pathway has been established as a therapeutic target for malaria. Similarly, the proteins of the vitamin B2 biosynthetic pathway are known to be essential in gram negative bacteria and in yeasts. We are planning to use our expertise in the metabolic pathways mentioned above as the basis for the development of robust and rapid assay methods that are suitable for robotic processing. Specifically, assays will be developed for 4 enzymes of the non-mevalonate pathway and for 3 assays of the riboflavin pathway. All assays will be designed for photometric monitoring and will be suitable for the screening of large libraries comprising hundreds of thousands of chemical compounds. Based on our prior work, we can already say with certainty that the required reagents can be procured with an acceptable effort. These assays are planned to be used for the screening of a 100,000 compound library of drug like compounds at the High Throughput Screening Laboratory at the University of Kansas in cooperation with Profs. Cushman, George and Ye. Additional assay methods will be developed for rapid verification of hits obtained in these screens. Follow-up work in cooperation with Prof. Cushman will be directed at the development of candidate compounds into actual anti-infective drugs by medicinal chemistry methods.